This invention relates to control devices for internal combustion engines wherein the amount of fuel supply, ignition timing, etc., are adjusted during the transient accelerated or decelerated state of the engine.
Control devices for internal combustion engines are now commonly used in which the appropriate amount of fuel supply and ignition timing are calculated on the basis of the relationship between the amount or pressure of the intake air and the rpm (revolutions per minute) of the engine, and the fuel injection valve and the ignition device are controlled accordingly. Further, Japanese laid-open patent application No. 62-85148 proposes a control device in which for the purpose of accomplishing a high precision control, the combustion pressure within the cylinders of the engine is detected so that it is adjusted to a target value thereof; in this type of the control device, the combustion state of the engine is detected by the combustion pressure sensors disposed on respective cylinders, and the fuel injection timing and the EGR (exhaust gas recirculation) valve are controlled such that the combustion state of the engine approaches a predetermined pattern.
This type of control device for internal combustion engines, however, has the following disadvantage: The fuel injection timing and the EGR ratio utilized as the manipulated variables in this type of device are effective for controlling the combustion pressure only over a small range thereof. In the case of automotive engines, however, the operating state of the engine often undergoes rapid changes over a wide range; thus, when, for example, the engine is rapidly accelerated, the engine is deviated from its optimum combustion state.